If all of those cleaning and elimination solutions don't do the trick, you might want to call in professional help. You've cleaned your home and eliminated any gnat attractors, but they're still ...

Thoroughly dry your sink and drain after cleaning, as gnats are attracted to damp areas." Gnats find standing water ...

after cleaning. The sanitize step is essential for killing pathogens. Pots and pans which were washed and rinsed but not sanitized must be sanitized before use. — Observed a significant gnat ...